/* ============================================================
   BASE — reset, typography, layout primitives, buttons
   ============================================================ */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  font-family: var(--font-body);
  background: var(--bg-primary);
  color: var(--text);
  line-height: 1.7;
  font-size: 16px;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}
body.no-scroll { overflow: hidden; }
a { color: var(--blue); text-decoration: none; transition: color var(--transition); }
a:hover { color: var(--navy); }
img { max-width: 100%; display: block; }
ul, ol { list-style: none; }
h1,h2,h3,h4,h5,h6 { font-family: var(--font-heading); font-weight: 700; line-height: 1.3; color: var(--text-strong); }
::selection { background: var(--blue); color: #fff; }

/* Scrollbar */
::-webkit-scrollbar { width: 10px; }
::-webkit-scrollbar-track { background: var(--bg-secondary); }
::-webkit-scrollbar-thumb { background: #cbd6df; border-radius: 5px; }
::-webkit-scrollbar-thumb:hover { background: var(--blue); }

/* Container */
.container { max-width: 1280px; margin: 0 auto; padding: 0 24px; }

/* SPA page sections */
.page-section { display: none; }
.page-section.active { display: block; }

/* Buttons */
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 11px 39px; border-radius: 50px; font-weight: 600; font-size: 15px;
  cursor: pointer; transition: all var(--transition); border: none; text-decoration: none;
  font-family: var(--font-body);
}
.btn-primary { background: var(--gradient); color: #fff; box-shadow: 0 6px 18px rgba(0,108,238,0.25); }
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 10px 26px rgba(0,108,238,0.35); color: #fff; }
.btn-outline { background: #fff; border: 2px solid var(--border); color: var(--navy); }
.btn-outline:hover { border-color: var(--blue); color: var(--blue); transform: translateY(-2px); }

/* Section titles */
.section-title { text-align: center; margin-bottom: 48px; }
.section-subtitle {
  display: inline-block; font-size: 13px; font-weight: 700; text-transform: uppercase;
  letter-spacing: 3px; color: var(--blue); margin-bottom: 12px;
}
.section-title h2 { font-size: clamp(1.8rem, 3vw, 2.6rem); color: var(--text-strong); }

/* Scroll reveal */
.fade-in-up { opacity: 0; transform: translateY(28px); transition: opacity 0.6s ease, transform 0.6s ease; }
.fade-in-up.visible { opacity: 1; transform: translateY(0); }

/* Scroll-to-top */
.scroll-top {
  position: fixed; bottom: 32px; right: 32px; z-index: 999;
  width: 48px; height: 48px; border-radius: 50%;
  background: var(--gradient); color: #fff; border: none;
  font-size: 20px; cursor: pointer; opacity: 0; visibility: hidden;
  transition: all var(--transition); box-shadow: 0 6px 20px rgba(0,108,238,0.35);
}
.scroll-top.visible { opacity: 1; visibility: visible; }
.scroll-top:hover { transform: translateY(-4px); }